How to approach seller for owner financing

[Spencer Rossie]

I'm a rookie investor and have found a property that would be better suited for me if the seller was willing to owner financing. How exactly do I approach the seller on this? From what I have found the owner owes right around what he is asking on the property. Is Subject 2 something I pursue first? Or should I jump right to owner financing? What questions should I be asking the seller to help me decide the right approach? Is there any due diligence I should be doing to help find the best avenue?  

The property needs serious rehab and looks to be around 50% occupied (20 units in total). If some additional numbers would help answering a few of these questions I can post them. Thanks!